Io (Eye-oh) – The Pizza Moon
Think of a giant pizza, with melted cheese, tomato sauce, and ripe olives. That’s what Io, the most volcanically active body in the solar system, looks like. “Toppings” on the surface are actually sulfur in different colorful forms. Jupiter’s strong gravity causes 300-foot-high “tides” in Io’s solid surface. (The difference between the lowest and highest ocean tides on Earth is “only” about 60 feet!)

Europa - The Ocean Moon
Think of Earth’s South Pole, a frozen mass with an ocean underneath. That’s Europa. Under an icy crust, Europa may have oceans as deep as 30 miles or more. Altogether, Europa is believed to have twice as much water as Earth.

Ganymede – The Rocky Moon
Think of a huge, magnetic rock. With a diameter of 3,280 miles, Ganymede has mountains, valleys, craters, and lava flows covered with rock and ice, plus its own magnetic field. Ganymede is Jupiter’s largest moon and the largest in our solar system. If it orbited the Sun instead of Jupiter, it would be a planet.

Callisto – The Oldest Moon
Think of a dimpled golf ball. That’s Callisto. About 4 billion years old, Callisto has the oldest landscape in the solar system, the most craters, and no volcanic activity.

If measuring by mean circumference, Jupiter is 11 times larger than Earth. There are many other ways to measure it, such as mass, volume, surface area, and density. If going by mass, then yes, Jupiter is far larger than 11 Earths...317 times larger actually. Pretty big!

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